Cotton planting is well underway in the past 3 weeks now that the weather turned warm. While the initial planting was cool and intermittently wet, temperatures since April 16th in the San Joaquin Valley have been excellent for planting cotton. Looking at temperature conditions from March 1 to April 26, 2012 according to accumulated degree-days > 60◦ F five days after planting, Shafter and Five Points had 47% and 37% of those days in the Adequate to Ideal categories (Figure 1).

Since April 15th, all dates have had ideal heat accumulation five days after planting (Figure 2A). These data are based on actual temperatures rather than forecasted data. While the forecasted (predicted) degree day accumulation 5 days post planting varied from actual temperature recordings, this year it under-estimated the degree day total (e.g. more conservative) more than it over-estimated (Figure 2B). Some of the the difference can be attributed to inaccuracy in predicting temperatures five days out and the generalized nature of forecast as compared to actual site recording.

The cotton is germinating and emerging from the soil very nicely. In the warm days since April 15th, most cotton should have germinated 10-14 days after planting. Getting a good, vigorous stand is a fundamental step in developing a season long IPM plan. Assessing your stand to determine the number of plants/acre is a useful indicator to address replant concerns and future management decisions. Guidelines for assessing your stand can be found by clicking here on Cotton Year Round IPM site.